nova compute
#2

Description

OpenStack Compute, codenamed Nova, is a cloud computing fabric controller. In
addition to its "native" API (the OpenStack API), it also supports the Amazon
EC2 API.
.
This charm provides the Nova Compute hypervisor service and should be deployed
directly to physical servers.

Overview

Usage

cloud-compute - Used to relate (at least) with one or more of
nova-cloud-controller, glance, ceph, cinder, mysql, ceilometer-agent,
rabbitmq-server, neutron

nrpe-external-master - Used to generate Nagios checks.

Database

Nova compute only requires database access if using nova-network. If using
Neutron, no direct database access is required and the shared-db relation need
not be added.

Networking

This charm support nova-network (legacy) and Neutron networking.

Storage

This charm supports a number of different storage backends depending on
your hypervisor type and storage relations.

In order to have cinder ceph rbd support for Openstack Ocata and newer
releases, ceph-access relation must be added to cinder-ceph to allow
nova-compute units to communicate with multiple ceph backends using
different cephx keys and user names.

NFV support

This charm (in conjunction with the nova-cloud-controller and neutron-api charms)
supports use of nova-compute nodes configured for use in Telco NFV deployments;
specifically the following configuration options (yaml excerpt):

In this example, compute nodes will be configured with 60% of available RAM for
hugepage use (decreasing memory fragmentation in virtual machines, improving
performance), and Nova will be configured to reserve CPU cores 0 and 2 and
1024M of RAM for host usage and use the supplied PCI device whitelist as
PCI devices that as consumable by virtual machines, including any mapping to
underlying provider network names (used for SR-IOV VF/PF port scheduling with
Nova and Neutron's SR-IOV support).

The vcpu-pin-set configuration option is a comma-separated list of physical
CPU numbers that virtual CPUs can be allocated to by default. Each element
should be either a single CPU number, a range of CPU numbers, or a caret
followed by a CPU number to be excluded from a previous range. For example:

yaml
vcpu-pin-set: "4-12,^8,15"

The pci-passthrough-whitelist configuration must be specified as follows:

A JSON dictionary which describe a whitelisted PCI device. It should take
the following format:

Configuration

(boolean)
If True enables openstack upgrades for this charm via juju actions.
You will still need to set openstack-origin to the new repository but
instead of an upgrade running automatically across all units, it will
wait for you to execute the openstack-upgrade action for this charm on
each unit. If False it will revert to existing behavior of upgrading
all units on config change.

(string)
Only used when migration-auth-type is set to ssh.
.
Full path to authorized_keys file, can be useful for systems with
non-default AuthorizedKeysFile location. It will be formatted using the
following variables:
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homedir - user's home directory
username - username
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(int)
This value dictates the number of replicas ceph must make of any
object it stores within the nova rbd pool. Of course, this only
applies if using Ceph as a backend store. Note that once the nova
rbd pool has been created, changing this value will not have any
effect (although it can be changed in ceph by manually configuring
your ceph cluster).

(int)
Defines a relative weighting of the pool as a percentage of the total
amount of data in the Ceph cluster. This effectively weights the number
of placement groups for the pool created to be appropriately portioned
to the amount of data expected. For example, if the ephemeral volumes
for the OpenStack compute instances are expected to take up 20% of the
overall configuration then this value would be specified as 20. Note -
it is important to choose an appropriate value for the pool weight as
this directly affects the number of placement groups which will be
created for the pool. The number of placement groups for a pool can
only be increased, never decreased - so it is important to identify the
percent of data that will likely reside in the pool.

(string)
Set to 'host-model' to clone the host CPU feature flags; to
'host-passthrough' to use the host CPU model exactly; to 'custom' to
use a named CPU model; to 'none' to not set any CPU model. If
virt_type='kvm|qemu', it will default to 'host-model', otherwise it will
default to 'none'. Defaults to 'host-passthrough' for ppc64el, ppc64le
if no value is set.

(string)
Default compute node availability zone.
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This option determines the availability zone to be used when it is not
specified in the VM creation request. If this option is not set, the
default availability zone 'nova' is used.
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NOTE: Availability zones must be created manually using the
'openstack aggregate create' command.
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(boolean)
Configure libvirt or lxd for live migration.
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Live migration support for lxd is still considered experimental.
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NOTE: This also enables passwordless SSH access for user 'root' between
compute hosts.

(string)
Block devices to use for storage of ephermeral disks to support nova
instances; generally used in-conjunction with 'encrypt' to support
data-at-rest encryption of instance direct attached storage volumes.

(string)
Cloud instances provide ephermeral storage which is normally mounted
on /mnt.
.
Setting this option to the path of the ephemeral mountpoint will force
an unmount of the corresponding device so that it can be used for as the
backing store for local instances. This is useful for testing purposes
(cloud deployment is not a typical use case).

(boolean)
Force conversion of backing images to raw format. Note that the conversion
process in Pike uses O_DIRECT calls - certain file systems do not support this,
for example ZFS; e.g. if using the LXD provider with ZFS backend, this option
should be set to False.

(string)
The percentage of system memory to use for hugepages eg '10%' or the
total number of 2M hugepages - eg "1024".
For a systemd system (wily and later) the prefered approach is to enable
hugepages via kernel parameters set in MAAS and systemd will mount them
automatically.
.
NOTE: For hugepages to work it must be enabled on the machine deployed
to. This can be accomplished by setting kernel parameters on capable
machines in MAAS, tagging them and using these tags as constraints in the
model.

(string)
Tell Nova which libvirt image backend to use. Supported backends are rbd
and qcow2. If no backend is specified, the Nova default (qcow2) is
used. Note that rbd imagebackend is only supported with >= Juno.

(string)
Used by the nrpe-external-master subordinate charm. A string that will be
prepended to instance name to set the host name in nagios. So for
instance the hostname would be something like:
.
juju-myservice-0
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If you're running multiple environments with the same services in them
this allows you to differentiate between them.

(string)
Repository from which to install. May be one of the following:
distro (default), ppa:somecustom/ppa, a deb url sources entry or a
supported Ubuntu Cloud Archive (UCA) release pocket.
.
Supported UCA sources include:
.
cloud:<series>-<openstack-release>
cloud:<series>-<openstack-release>/updates
cloud:<series>-<openstack-release>/staging
cloud:<series>-<openstack-release>/proposed
.
For series=Precise we support UCA for openstack-release=
* icehouse
.
For series=Trusty we support UCA for openstack-release=
* juno
* kilo
* ...
.
NOTE: updating this setting to a source that is known to provide
a later version of OpenStack will trigger a software upgrade.
.

(string)
The pci-passthrough-whitelist option of nova-compute charm is used for
specifying which PCI devices are allowed passthrough. pci-alias is more
a convenience that can be used in conjunction with Nova flavor properties
to automatically assign required PCI devices to new instances. You could,
for example, have a GPU flavor or a SR-IOV flavor:
.
pci-alias='{"vendor_id":"8086","product_id":"10ca","name":"a1"}'
.
This configures a new PCI alias 'a1' which will request a PCI device with
a vendor id of 0x8086 and a product id of 10ca.
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For more information about the syntax of pci_alias, refer to
https://docs.openstack.org/ocata/config-reference/compute/config-options.html

(string)
Sets the pci_passthrough_whitelist option in nova.conf which allows PCI
passthrough of specific devices to VMs.
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Example applications: GPU processing, SR-IOV networking, etc.
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NOTE: For PCI passthrough to work IOMMU must be enabled on the machine
deployed to. This can be accomplished by setting kernel parameters on
capable machines in MAAS, tagging them and using these tags as
constraints in the model.

(boolean)
If True enables IPv6 support. The charm will expect network interfaces
to be configured with an IPv6 address. If set to False (default) IPv4
is expected.
.
NOTE: these charms do not currently support IPv6 privacy extension. In
order for this charm to function correctly, the privacy extension must be
disabled and a non-temporary address must be configured/available on
your network interface.

(boolean)
Use a multipath connection for iSCSI volumes. Enabling this feature
causes libvirt to discover and login to available iscsi targets before
presenting the disk via device mapper (/dev/mapper/XX) to the VM instead
of a single path (/dev/disk/by-path/XX). If changed after deployment,
each VM will require a full stop/start for changes to take affect.

(float)
The CPU core multiplier to use when configuring worker processes for
this services e.g. metadata-api. By default, the number of workers for
each daemon is set to twice the number of CPU cores a service unit has.
When deployed in a LXD container, this default value will be capped to 4
workers unless this configuration option is set.

Relations
Relations enable services to easily and securely share information with each other.